My steering wheel vibrated a lot at around 80km/h. I had the wheels balanced, wheel alignment done, put the stock 17's back on and nothing altered it. I had replaced a drive shaft previously (and swapped to a 4.1 diff) and in desperation rotated the tailshaft one bolt hole on the diff flange...Presto vibration gone. It's not hard to do and only takes 10 mins one the car's jacked up.